net: renesas: rswitch: align mdio C45 operations with datasheet

Per rswitch datasheet, software can know that mdio operation completed
either by polling MPSM.PSME bit, or via interrupt.

Instead, the driver currently polls for interrupt status bit. Although
this still provides correct result, it requires additional register
operations to clean the interrupt status bits, and generally looks wrong.

Fix it to poll MPSM.PSME bit, as the datasheet suggests.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://patch.msgid.link/20241216071957.2587354-4-nikita.yoush@cogentembedded.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/renesas/rswitch.c b/drivers/net/ethernet/renesas/rswitch.c
index e1541a2..6e3f162 100644 (file)
--- a/drivers/net/ethernet/renesas/rswitch.c
+++ b/drivers/net/ethernet/renesas/rswitch.c
@@ -1205,32 +1205,26 @@ static int rswitch_etha_set_access(struct rswitch_etha *etha, bool read,
        if (devad == 0xffffffff)
                return -ENODEV;
 
-       writel(MMIS1_CLEAR_FLAGS, etha->addr + MMIS1);
-
        val = MPSM_PSME | MPSM_MFF_C45;
        iowrite32((regad << 16) | (devad << 8) | (phyad << 3) | val, etha->addr + MPSM);
 
-       ret = rswitch_reg_wait(etha->addr, MMIS1, MMIS1_PAACS, MMIS1_PAACS);
+       ret = rswitch_reg_wait(etha->addr, MPSM, MPSM_PSME, 0);
        if (ret)
                return ret;
 
-       rswitch_modify(etha->addr, MMIS1, MMIS1_PAACS, MMIS1_PAACS);
-
        if (read) {
                writel((pop << 13) | (devad << 8) | (phyad << 3) | val, etha->addr + MPSM);
 
-               ret = rswitch_reg_wait(etha->addr, MMIS1, MMIS1_PRACS, MMIS1_PRACS);
+               ret = rswitch_reg_wait(etha->addr, MPSM, MPSM_PSME, 0);
                if (ret)
                        return ret;
 
                ret = (ioread32(etha->addr + MPSM) & MPSM_PRD_MASK) >> 16;
-
-               rswitch_modify(etha->addr, MMIS1, MMIS1_PRACS, MMIS1_PRACS);
        } else {
                iowrite32((data << 16) | (pop << 13) | (devad << 8) | (phyad << 3) | val,
                          etha->addr + MPSM);
 
-               ret = rswitch_reg_wait(etha->addr, MMIS1, MMIS1_PWACS, MMIS1_PWACS);
+               ret = rswitch_reg_wait(etha->addr, MPSM, MPSM_PSME, 0);
        }
 
        return ret;

diff --git a/drivers/net/ethernet/renesas/rswitch.h b/drivers/net/ethernet/renesas/rswitch.h
index 78c0325..2cb66f3 100644 (file)
--- a/drivers/net/ethernet/renesas/rswitch.h
+++ b/drivers/net/ethernet/renesas/rswitch.h
@@ -743,12 +743,6 @@ enum rswitch_etha_mode {
 #define MPSM_PRD_SHIFT         16
 #define MPSM_PRD_MASK          GENMASK(31, MPSM_PRD_SHIFT)
 
-/* Completion flags */
-#define MMIS1_PAACS             BIT(2) /* Address */
-#define MMIS1_PWACS             BIT(1) /* Write */
-#define MMIS1_PRACS             BIT(0) /* Read */
-#define MMIS1_CLEAR_FLAGS       0xf
-
 #define MLVC_PLV               BIT(16)
 
 /* GWCA */